Answer: D. Energy is always conserved
Explanation: The law of energy conservation says that energy is neither created or destroyed, that it is only transferred or transformed from energy. "Conserved" means to maintain a constant overall total, which ties directly into the law of conservation (Energy can't be created nor destroyed, it can only be transferred or transformed from one form to another).
C metal. most metals are a conductor which an electric current is attracted to.
Answer:
<h3>75m</h3>
Explanation:
If a cat walk 100m East, this means that it is walking in the positive x direction, the distance will therefore be +100m
If it turns around and walks 25 m west, the direction of movement is in the negative x direction i.e -25m
Taking the sum;
Displacement = +100m - 25m
Displacement of the cat = 75m
hence the cats displacement is 75m
Answer:
D) 3.0
Explanation:
As we know that
So,
Now
T = True weight of object
= mg
= 245 N
W = apparent weight = 200 N
= density of object
Now we use the formula
buoyancy force = True weight - W
600 V (9.8) = 45
V = 0.007653
m = 25 kg
And as we know that
= 3266.7
Now
specific gravity is
= 3.2
Hence, the correct option is d.
Answer:
Explanation:
At height h , potential energy of coaster car having mass m = mgh .
The car will lose potential energy and gain kinetic energy.
height lost by car when it is at the top of loop of radius R
= h - 2R
potential energy lost = mg ( h - 2R )
kinetic energy gained = mg ( h - 2R )
kinetic energy = 0 + mg ( h - 2R )
= mg ( h - 2R )
b )
For the car to remain in contact with the track , if v be the minimum velocity
centripetal force at top = mg
m v² / R = mg
v² = gR
kinetic energy = 1/2 mv²
= 1/2 m x gR
= mgR /
If h be the minimum height that can give this kinetic energy
mg ( h - 2R ) = mgR / 2
h - 2R = R / 2
h = 2.5 R .